/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.hadoop.hive.ql.exec;

import org.apache.hadoop.hive.ql.metadata.HiveException;
import org.apache.hadoop.hive.ql.plan.exprNodeConstantDesc;
import org.apache.hadoop.hive.serde2.objectinspector.InspectableObject;
import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspector;
import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspector;
import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspectorFactory;

public class ExprNodeConstantEvaluator extends ExprNodeEvaluator {

  protected exprNodeConstantDesc expr;
  transient ObjectInspector objectInspector;
  
  public ExprNodeConstantEvaluator(exprNodeConstantDesc expr) {
    this.expr = expr;
    objectInspector = ObjectInspectorFactory.getStandardPrimitiveObjectInspector(expr.getTypeInfo().getPrimitiveClass());
  }

  public void evaluate(Object row, ObjectInspector rowInspector,
      InspectableObject result) throws HiveException {
    assert(result != null);
    result.o = expr.getValue();
    result.oi = objectInspector;
  }

  public ObjectInspector evaluateInspector(ObjectInspector rowInspector)
      throws HiveException {
    return objectInspector;
  }
}
